98 ANNUAL OF SCIENTIFIC DISCOVERY. 



really an invention or improvement, or only a questionable modifi- 

 cation, at least shows the extraordinary activity of North Ameri- 

 can thought." 



As a commentary on the above, we may add a report from Com- 

 missioner Beckvvith to the Department of State, showing that of 

 the 524 United States exhibitors at Paris, 262, or exactly one-half, 

 received honorable awards. These awards include 4 grand prizes, 

 17 gold medals, 52 silver medals, 103 bronze medals, and honora- 

 ble mention of 79 exhibitors. 



Hottina. This is a powder compounded by M. Hottin, of 

 Paris, for making linen fire-proof without impairing its white- 

 ness, when mixed about equally with the starch, a like quantity 

 of gum being also added. It is prepared by adding a little 

 ammonia to a solution of phosphoric acid lime, and filtering with 

 animal carbon, then evaporating until concentrated, when 5 

 per cent, of gelatinous silicic acid is added, and the whole evapo- 

 rated to a crystal substance and pulverized. 



Berlin Ware. This ware, so celebrated among chemists for its 

 power of withstanding the action of heat, acids, and alkalies, is 

 made from the following paste : 45 parts kaolin, 37.5 parts alu- 

 mina, 16.5 parts felspar. The glaze is composed of 42 parts sand, 

 33 parts kaolin, 13 parts unburned gypsum, and 12 parts of broken 

 unglazed fired paste as above. Dingler's Polytecli. Jour. 



Lucifer Matches without Phosphorus. In the third edition of 

 " Knapp's Chemical Technology," the following formula is given : 

 3 parts of sulphide of antimony, 16 parts chlorate of potash, 1 part 

 bichromate of potash, 10 parts red lead, 8 parts nitromannite, 4 

 * parts powdered glass, and 5 parts of gum. The nitromannite 

 makes the match more easily ignited. This substance is easily 

 prepared by treating mannite with nitric acid, or a mixture of ni- 

 tric and sulphuric acid, in the same way as cotton for the manu- 

 facture of gun-cotton. 



Bleaching Process. According to the chemist Bolley, hypo- 

 chlorite of magnesia bleaches much more quickly than the hypo- 

 chlorite of lime ; it has also another advantage of not first coloring 

 the straw brown before it bleaches it. He explains the difference 

 in the action by showing that magnesia is a much weaker base 

 than lime, and consequently parts with its chlorine more readily. 



Cement for attaching Glass and Brass. A resin soap is first 

 formed by boiling 3 parts of resin and 1 part of caustic soda in 5. 

 parts of water, and then mixing this with half its weight of plaster 

 of Paris. This cement is said to be impervious to petroleum, only 

 superficially affected by water, to adhere very strongly, and to be 

 a bad conductor of heat. 



Malleable Glass. A piece of St. Gobain glass, prepared a long 

 time ago by M. Pelouze, had lost its transparency from devitrifica- 

 tion, but had not changed in density. This piece, supported by 

 one extremity, having been placed in a drawer, was found, after 

 some days, to have become curved under its own weight, having in 

 fact become malleable glass ; the surface at the same time was 

 covered with efflorescence. Pliny, in his history, speaks of a glass 



